The growth rate of cosmic structure is a powerful cosmological probe for extracting information on the gravitational interactions and dark energy. In the late time Universe, the growth rate becomes non-linear and is usually probed by measuring the two point statistics of galaxy clustering in redshift space up to a limited scale, retaining the constraint on the linear growth rate f . In this letter, we present an alternative method to analyse the growth of structure in terms of local densities, i.e. f (∆). Using N-body simulations, we measure the function of f (∆) and show that structure grows faster in high density regions and slower in low density regions. We demonstrate that f (∆) can be modelled using a log-normal Monte Carlo Random Walk approach, which provides a means to extract cosmological information from f (∆). We discuss prospects for applying this approach to galaxy surveys.